Soldering instead of crimping

I installed all the wiring my race car and used both crimp and solder. I had rain on the connections while trailering on the road along with massive vibration on the connections. For small wiring I used crimp only but always used shrink sleeve and supported the connection with two inches. On larger connections I crimped and soldered then used shrink sleeve and supported within two inches. 14 years on the car and never had an electrical issue. It takes more time to shrink sleeve each connection but that seals out moisture and adds some support to the joint. I have also used paint on electrical goo which turns solid in the open air. it works but I don't believe it holds up as well as shrink sleeve. I soldered on the larger connections as I was worried about losing some electrical transfer but I never actually saw any need for it.

MotorPro wrote:
Simpe answer--either one done correcty will last---either one done poorly will not last

Crimp actually outlasts solder due to the fatigue issues I mentioned. Look in a rocket ship, satellite, or airplane and you will see crimps. Solder can only be used with appropriate strain relief to avoid the stress concentration next to the solder joint....then and only then will it compare to a (good) crimp for fatigue life.

I got help wiring my diy van from an industrial electrician friend.

He flatly refused to allow me to solder anything. Crimps are better with vibration and in any kind of short situation.

A few years ago, I posed the solder vs. crimp question to a product developement engineer for one of the larger suppliers of marine electrical wire, terminals and accessories. This is what he stated.

When properly crimped, tinned copper wire and properly sized tinned terminals do not require soldering. The crimping force generates enough pressure to fuse the tin on the wire to the tin on the terminal providing a near zero resistance to current flow.

The down side to soldering as well as crimping is that the copper in the wire as well as the terminal becomes brittle and subject to fatigue breakage. Copper is somewhat unique as a metal when it comes to heat treating. When steel is heated and allowed to cool slowly it becomes more maleable (softer) and flexible. Copper on the other hand becomes harder and more brittle when heated and allowed to cool slowly.

He did suggest however that high amperage terminals such as battery cable lugs be properly crimped as well as soldered. His reasoning was that if there is heat generated by the high amperage at the terminal, it could break the electrical bond of the thin tin plating and cause some resistance. Resistance causes more heat and that increases the resistance even more etc. etc. His reccomendation was that terminals 8 gauge and larger (6,4,2 ect.) be properly crimped and then soldered. The fatigue factor due to the tempering of the copper is not as large a factor due to the strength of the larger wire.

If soldering is to be done, only resin core solder is to be used, never acid core or soldering paste. As well, the solder should be 50/50 (lead/tin) or better. The newer solders have replaced the lead with other metals (antimony?).

Lastly, he emphasized that the connection, especially in the marine enviroment, must be sealed to prevent corrosion from water and humidity. Adhesive lined heat shrink is highly recomended as well as anti-corrosion spray or grease.

We have been using the above proceedures for many years in commercial boats used in extreme salt water enviroments. None of our connections have failed at the wire/terminal connection.

I get it that crimps seem to be the better choice but it brings up the question of what is a proper crimp tool. Some of the cheap stuff I see does not look like it will do that good of a job. I'm guessing that on most crimping tools you need a nib that pushes down both sides at the crimp split, not just mashing everything.

Raften wrote:
I get it that crimps seem to be the better choice but it brings up the question of what is a proper crimp tool. Some of the cheap stuff I see does not look like it will do that good of a job. I'm guessing that on most crimping tools you need a nib that pushes down both sides at the crimp split, not just mashing everything.

Within this thread there are some links.

Looked at the three links to crimpers but did not find any with a middle nib so guess it must not be a factor. The 3M did look like it might on the biggest opening. Still ever time I buy a item that has a good crimp seem to be better formed instead of mashed flat. Yea, I know, picky.

Raften wrote:
Looked at the three links to crimpers but did not find any with a middle nib so guess it must not be a factor. The 3M did look like it might on the biggest opening. Still ever time I buy a item that has a good crimp seem to be better formed instead of mashed flat. Yea, I know, picky.

the sargent crimper (see link in previous post) has many inserts you can use. For non insulated "split" ring connectors, they have and I use one of the inserts that crimps the ring with the classic two simicircles onto the wires. nylon insulated connectors take a different crimp form as do the ones with heat shrink. I have about 10 jaw sets for the sargent crimper for different types of connectors. non insulated connectors that aren't "split" ring take yet another crimp form.

OK found a Ideal crimper, like the sargent, in the pawn shop. Still does not have the jaws I am looking for but I can order those.

If your set on soldering after crimping and are not highly skilled and knowlegable about soldering and don't have all the proper tools I'd suggest buying adhesive lined heat shrink crimp connectors with a built in solder preform. Then use good marine grade tinned wire. Use the proper crimp tool and a real heat gun to heat seal and solder the connection.

Even though I have all the tools for soldering and the skills, for the few cases when I want a crimped and soldered connection, I use the solder filled heat sealed connectors. Gives a crimp joint with solder along with the proper strain relief to minimize the chances of flex failure. the connector is designed so the heat shrink extends beyond the solder joint.